The present invention relates to apparatus for straightening the frame of a damaged vehicle. More particularly, the frame straightening apparatus of the subject invention incorporates primary and secondary towers that selectively push or pull the frame and simultaneously hold the frame at selected locations to effectively straighten the frame of the vehicle of critical importance is the reduction of the time required for carrying out the frame straightening operation by the subject invention as compared with prior known apparatus.
Prior to the instant invention various kinds of vehicle frame straightening equipment have been developed, most of which incorporate pulling devices, for purposes of straightening the frame of a Vehicle. Some examples of the apparatus that have incorporated different kinds of mechanisms for carrying out a frame straightening operation are illustrated in the U.S. Pat. No. 3,518,867 to Rouis; Whitney U.S. Pat. No. 3,556,482; Larson et al U.S. Pat. No. 3,999,419; Borup U.S. Pat. No. 4,050,287; Specktor U.S. Pat. No. 4,248,079; Jarman et al U.S. Pat. No. 4,296,626; and Eck U.S. Pat. No. 4,313,335.
As will be noted in the above referred-to U.S. Patents, apparatus for straightening vehicle frames have incorporated pulling devices which include a chain having a hook attached to the outermost end thereof that is normally secured to a selected portion of the frame on which a pulling action is exerted. Such pulling chains are normally operatively interconnected to a piston of a hydraulic cylinder which upon actuation exerts the necessary pulling force for carrying out the frame straightening operation. Examples of this type of equipment are illustrated in the U.S. Pat. No. 4,296,626 to Jarman et al, and Eck U.S. Pat. No. 4,313, 335. Other apparatus utilize beams that are movable to exert a pulling action through a chain or the like for straightening the vehicle frame and such equipment is illustrated in the U.S. Pat. No. 3,556,482 to Whitney, and Larson et al U.S. Pat. No. 3,999,419. The other patents referred to above also show various kinds of pulling devices that are generally designed to exert a pulling action on a selected portion of a frame for carrying out the frame straightening operation.
In all of the referred to patents as indicated hereinabove, the vehicle must be secured in place and this has been usually accomplished by attaching a series of chains to the vehicle frame and to a fixed frame location. Conventional pinch weld clamps are also commonly used in unitized frames to hold the vehicle frame in a fixed position. In the prior known apparatus the straightening operation was generally accomplished by exerting a pulling action on the frame that was created by the use of the chains which as described were interconnected to pistons of hydraulic cylinders or the like. It is significant that in all of the patents as referred to herein, none of them effectively carry out the frame straightening operation without considerable set-up time which requires a great deal of effort on the part of the users of the equipment; and it is not uncommon for a frame straightening machine to require several hours of set-up time and several more hours to carry out the frame straightening operation. This considerable expenditure of time in setting up and carrying out the frame straightening operation substantially increased the cost of the procedure for the owner of the equipment, and the equipment is not only difficult for the user to operate effectively, but further results in unreasonably high costs to the owner of the vehicle.
As will be set forth hereinafter, the frame straightening apparatus of the subject invention reduces the set-up time for placing the equipment in proper location and for more effectively carrying out the frame straightening operation, all to the benefit of the owner of the vehicle in that costs for the straightening operation are effectively reduced.